In skin-care stories, free radicals always play the villain and antioxidants the hero. Even if you have very limited knowledge of free radicals, you probably know you want to avoid them and the damage that ensues when they interact with our skin. But why? We got the scientific background on how free radicals cause damage and expert advice on how to protect your skin.

What are free radicals?

“Free radicals are unstable molecules that search for electrons to stabilize themselves,” explains Washington, D.C. dermatologist Tina Alster, MD. She adds that the cells in our skin are the perfect target for free radicals to “steal” electrons, causing our cells to mutate, which is where the damage comes in.

Where do free radicals come from?

Free radicals can be generated both internally and externally. Internal free radicals are derived from metabolic processes such as hormone fluctuations and emotional stress, says Dr. Alster. The genesis of a free radical externally is a bit scientific, but Fort Lauderdale, FL dermatologist Dr. Matthew Elias walks us through the process slowly.

“The skin is made up of lots and lots of molecules that all coexist together in a steady, peaceful way. Unfortunately sometimes that balance gets thrown off, typically due to inflammatory inducing processes like sunlight, smoking, pollution, stress, etc., and the skin is no longer in harmony,” explains Dr. Elias. “If any of the molecules in the skin get knocked out of whack due to inflammation they essentially lose an electron, and that is the ‘free radical’ that then scavenges around looking to steal that electron back from another molecule.” This then results in a cascading event where each molecule will try to steal from the next, which ultimately leads to free radical damage and skin that appears damaged.

Why would we want to avoid free radicals? What are some of their potential negative effects?

The previously explained process can do some serious damage to our skin, from inflammation to photoaging. “Beyond being a precursor to skin cancer and malignant melanoma (which can be fatal), free radicals are also a major cause of premature skin aging,” says Dr. Alster. Additionally, “when a mutated cell replicates, a copy of the mutation is created, which can worsen skin conditions like hyperpigmentation and melanoma.”

How do antioxidants work against free radicals?

When talking about the many merits of antioxidants, fighting free radicals is often at the top of the list, but how exactly do antioxidants help protect against free radical damage? Simply put, “antioxidants neutralize free radicals by blocking the mutation of healthy cells,” says Dr. Alster. To dive a bit deeper, Dr. Elias explains that “antioxidants neutralize the free radical by donating the missing electron, preventing the cascade and ultimately stabilizing the skin and allowing it to return to its normal function.” Once the free radical is stable and is no longer on the hunt for the electron, skin will return to replicating healthy, normal skin cells rather than mutations, notes Dr. Alster.

What are some ways to reduce free-radical damage?

Experts agree that the best way to reduce free radical damage is consistently using sunscreen. Dr. Elias suggests Isdin Eryfotona Actinica, ($60) Alastin Hydratint ($60) or SkinMedica Total Defense +Repair ($70). SPF of 30 or higher will help prevent free radicals from ever forming in the skin, says Dr. Alster. She also notes that it’s important to “avoid chemical air fresheners and house cleaning supplies, as well as cigarette smoke and other air pollutants that abound in large metropolitan areas” as much as possible.

Since antioxidants are such powerful defenders against free radical damage, we should all have a daily topical antioxidant in our skin-care routine. This antioxidant will “help protect and restore skin, especially after sun exposure in the summer months,” says Dr. Alster. Dr. Elias recommends Skinceuticals CE Ferulic ($169). Additionally, he advocates for an oral antioxidant like Heliocare Advanced ($37) (polypodium leucotomos plus niacinamide) “which has brisk data supporting its use to scavenge free radicals and prevent the cascade event from occurring.”